1. Field of the Invention
The present invention relates to a printing system in which a security watermark pattern lies in the background behind the primary page, and more particularly to a printing system and an image forming apparatus incorporated in the printing system in which a security watermark pattern is the information obtained in a non-contact manner from an employee ID card of a user who operates the image forming apparatus.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 2004-260273 discloses a conventional printing system in which a security watermark pattern lies in the background behind the primary page. A print driver is installed in a host computer of the printing system. The print driver inquires an administration host prior to a printing operation to determine whether the user is obliged not to leak information. If the user is obliged not to leak information, the security watermark is embedded into the print data to be printed before printing is performed, thereby preventing leakage of information. The information embedded in the security watermark is information that can identify a user name and a host computer that performs printing.
However, information on a host computer that performs printing and a user name of a person who logs on the host computer are not enough information to identify a person who actually takes out a printed document from a printer. In other words, the conventional printing system is not capable of preventing a malicious person from obtaining a password fraudulently and accessing another person's computer for classified information. Thus, a need exists for improved security of classified information.